Bricks, Masonry, Asphalt and Concrete - carpet on cracked floor

i'm doing a quick clean-up of my unfinished basement and i'd like to lay some extra carpet down on the concrete floor. while i've never seen water on the floors or any wetness on the basement floors, there are a number of big cracks and slightly buckled areas. in addition, one wall section is slightly crumbly to the touch. my questions:

1) if this is meant to be a quick fix (we're planning to completely rehab the basement in two years), should i expect there to be mold or mildew issues?

2) should i put anything between the carpet and the concrete floor?

3) is there anything i can do to level out the bumpy spots as a temporary fix?

BUMP to get a response for self :)